The 67-year-old, appearing for sentence on Friday, was jailed for three and-a-half years.

Judge Stephen Climie told Richards: “You were with a very vulnerable young child.

“You abused her trust to an extreme degree.”

He had denied all charges but been found guilty of three counts of indecent assault.

A jury cleared him of an allegation of gross indecency and they were discharged after failing to reach verdicts on five other counts of indecent assault, which were left to lie on the file.

Richards, who was living in South Wonston, near Winchester, during the trial, has been placed on the Sex Offenders Register for an indefinite period and made the subject of a five-year Sexual Harm Prevention Order, restricting his access to children.

She said he had taken advantage of the youngster and used her for his own "sexual gratification".

The court was told that Richards had kept in touch with the victim, who was under 13 at the time, and attempted to buy her silence.

“He was frightened that she would spill the beans,” Ms Henty said.

The prosecuting counsel said the victim had visited Richards at his home in 2002 to find him "sunbathing naked in his garden with his private parts exposed".

Ms Henty said the victim confronted Richards about the abuse, only to be told by him: “I’m just a paedophile.”

But during the trial, Richards described the alleged remark as "ridiculous", telling the jury: “Who is going to say things like that? It’s just something she has made up to bolster her story.”

The defendant, denying all the allegations, said: “None of this happened. It’s complete rubbish.”

Character witnesses at the trial included Stuart Shilson, who was assistant private secretary to the Queen from 2001 until 2004.

Mr Shilson, from Godalming, said he was happy for his own children to be with Richards.

Allegations hanging over him

His mother, Gillian Shilson, a writer, who has been Richards’ girlfriend after meeting him while they were students at the University for the Creative Arts in Farnham, also said she had never any suspicions about the defendant.

“I have huge love and respect for this dear man,” she said.

Miss Adrienne Knight, defending, said her client was of previous good character and had lived with the allegations hanging over him for nearly four years.

“It’s been like a suspended sentence,” she said.

The court was told that jurors had been unable to reach verdicts in an initial trial.

Reading an impact statement from the victim, Judge Climie said the girl had suffered recurring nightmares and flashbacks.

“It has had a significant impact on her psychological well-being,” he said.

Detective Constable Sharron Goodchild, from Surrey Police’s Sexual Offences Investigation Team, said: “I would like to commend the victim for her bravery in coming forward and giving evidence and hope that this demonstrates how seriously Surrey Police takes all allegations of sexual offences.

"We would continue to encourage people to report these matters and would like to reassure them that their allegations will be thoroughly investigated.”